[Clinical Practice Guidelines for diagnosis of organic involvement of amyloidosis: Part 3/3 Year 2020]

Method: Use the PICO format to generate a series of questions, focusing on the specificity and sensitivity of the amyloidosis diagnostic test. PubMed searches were conducted in English and Spanish from July to August 2019. The level of evidence and recommendation are based on the GRADE system (http://www.gradeworkinggroup.org/index.htm). The recommendations are graded according to their direction (for or against) and strength (strong and weak). Finally, it is recommended to use GLIA tools to evaluate the obstacles and facilitators in implementation. Suggested explanation A strong suggestion indicates a high degree of trust in support or opposition to the intervention. When defining a strong recommendation, this guide uses the "recommended" language. The weaker recommendations indicate that the outcome of the intervention (favorable or unfavorable) is doubtful. In this case, if a weak recommendation is defined, the "recommendation" language is used. How to use these guidelines: Recommendations must be explained within the scope of special care in validated diagnostic studies conducted by specially trained doctors. It is not assumed to change the coexistence conditions of the disease process. Presumably, the attending physician has a high degree of suspicion of amyloidosis. It assumes that diagnostic research is conducted by well-trained doctors using a validated standardized method. This guide is intended for health care professionals and those involved in health care policies to help ensure that the necessary agreements have been reached to provide appropriate care. Summary of recommendations For patients with suspected amyloidosis, it is recommended: Measured value of creatinine be used as a preliminary assessment for the diagnosis of renal involvement in patients with suspected renal amyloidosis. 24-hour proteinuria be measured and characterized to diagnose renal involvement in patients with suspected renal amyloidosis. Immunohistochemical staining of skin biopsy for patients genetically diagnosed with ATTR, for early diagnosis of neuropathy. The signs or symptoms of these patients suggest the presence of fine fiber neuropathy. Skin biopsy and immunohistochemical staining for early diagnosis of neuropathy. These patients show signs or symptoms suggesting fine fiber neuropathy. Conduct nerve conduction studies on motor and sensory fibers to diagnose total fiber neuropathy in patients who are diagnosed or suspected of having amyloidosis. Test (Sudoscan) is recommended for the early diagnosis of peripheral autonomic neuropathy (even in asymptomatic patients) in patients with suspected autonomic neuropathy due to amyloidosis. Ewing's standard to measure heart rate variability to diagnose autonomic hypofunction in patients with autonomic neuropathy suspected of having amyloidosis. Measure orthostatic hypotension to diagnose early autonomic hypotension for patients with amyloidosis or systemic amyloidosis suspected of autonomic neuropathy. It is suggested: QST test to diagnose neuropathy early for patients genetically diagnosed with ATTR, if they show signs or symptoms suggesting fine fiber neuropathy Measure alkaline phosphatase to initially assess liver involvement in patients with amyloidosis.